1. Field of the Invention
The invention relates generally to computer applications, systems and methods, and more particularly to computer systems and methods to communicate with host internal area access systems including host bridges, bridge exits, and program exits.
2. Description of the Related Art
Some conventional legacy host computer systems include host internal area access systems such as host bridges, bridge exits, and program exits to allow communication with one or more internal application programs running in internal transaction areas of the legacy host computer systems. A host internal area access system allows for one or more cycle points of the internal application programs, which give control of the internal application programs to external applications including host and client applications and modules that run outside of the internal transaction areas. This control of the internal application programs allows users of the external applications to access internal application program data, which would otherwise typically be accessed through antiquated legacy application systems. In order to access the internal application programs through a host internal area access system, the external applications typically communicate in languages oriented toward the internal transaction area of the legacy host computer system.
For instance, for its Customer Information Control System (CICS), International Business Machines (IBM) provides a host internal area access system, CICS 3270 Bridge, which allows access into CICS applications from an IBM 3270 terminal perspective. In this case, users of external applications running outside of the CICS system must first develop interfaces to communicate with host internal area access systems, such as the CICS 3270 Bridge, that are written in languages oriented to the internal transaction area of the host, such as CICS.
Unfortunately, expertise in internal transaction areas, such as CICS, is highly sophisticated, which tends to discourage development of communication between external applications and internal applications through host internal area access systems such as the CICS 3270 Bridge. This expertise typically includes knowledge of older programming and assembly languages and data structures involved with such languages as COBOL, PL/1, 370 Assembler and other languages. The expertise also generally includes, but is not limited to, the internal architecture, pseudo-conversational transactions, and conversational transactions of the internal transaction area, associated quasi-reentrant programming models, asynchronously started transactions, and continuity of multiple instantiations of multiple internal applications to achieve some overall goal.
Additionally, host internal area access systems are not designed to service other external applications such as terminal emulation applications that emulate terminals unrelated to the internal transaction area of the host computer system. Since the host internal area access systems, such as the CICS 3270 Bridge, are oriented to particular native terminals compliant with the internal transaction area 108 (such as IBM CICS), such as the IBM 3270 terminal, the host internal area access systems are not designed to handle non-native terminal communication, such as non-3270 terminal communication that is non-compliant with the internal transaction area, which further limits the utility of the host internal area access systems.
Furthermore, host internal area access systems typically do not readily facilitate secured transactions such as when usernames and passwords are used. Consequently, those involved with external applications must develop workarounds to address requirements associated with secured transactions such as providing usernames and passwords. These workarounds tend only to be partially satisfactory. For instance, external applications have limited ability to communicate with the host internal area access systems regarding aspects related to secure transactions, which results in the external applications having no feedback as to whether the usernames and passwords, which are sent, are correct. In cases when usernames and passwords are incorrectly provided by the external applications, the secured transactions with the host internal area access systems fail without indication of the failure provided to the external applications. Herein are described computer based systems and methods directed toward these and other issues.
Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings.